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This content is taken from the University of Strathclyde's online course, Introduction to Forensic Science. Join the course to learn more.

Skip to 0 minutes and 2 secondsThe next main challenge in Murder by the Loch is making sense of the evidence to assess if the case has reached the stage where it can be concluded in an investigative sense. This is a particular focus in module six, as you explore how to evaluate the evidence in a systematic manner by formulating specific hypotheses and testing them in the light of the evidence. In most countries, this completes the first stage of a criminal prosecution. And a complete case file of the evidence would then be submitted to the prosecuting authorities. We use a particular approach to this issue-- tabulating the hypotheses and the evidence that supports or contradicts them.

Skip to 0 minutes and 45 secondsSpecifying the hypotheses makes them clear and allows open discussion and challenge of them. This open discussion helps minimise the prejudices and biases that we all have as individuals because it compels us to justify our views in a reasoned way. This problem can be summed up by a quotation from the 18th-century write Lawrence Sterne. "It is the nature of a hypothesis, when once a man has conceived it, that it assimilates everything to itself, as proper nourishment; and from the first moment of your begetting it, generally grows stronger by everything that you see, hear, read, or understand." The process also highlights areas where questions remain unanswered or where the evidence is ambiguous. Our approach to this is illustrative.

Skip to 1 minute and 34 secondsWhilst these judgments must take place in an investigation, they may not be dealt with in this manner. The hypothesis being tested will, in some ways, be related to the six Ws, with the critical question being, who was the offender? You will now have realised that this issue can only be approached indirectly by addressing many other questions that point in this direction. There is a common misperception that the guilt of an individual can be established directly by forensic evidence. But this is not so. In many cases, the potential offender is identified on the basis of inferences drawn from the forensic evidence combined with the detailed circumstances of a case, such as where or when something happened.

Skip to 2 minutes and 21 secondsFor example, who started a fatal fire might be inferred from a shoe mark that links an individual to the scene. And although DNA and fingerprints can provide compelling evidence of identity, innocence or guilt are entirely separate matters. This may appear to be a subtle, perhaps even pedantic, distinction. But failure to recognise this on the part of scientists, lawyers, and judges has led to false convictions in the past and requires constant vigilance. You will explore this complex issue in this module.

Welcome to Week 6

In weeks one through five, the cases were presented as a narrative of events as they unfolded, and reflected the areas of forensic science that we selected to illustrate this introduction to the subject.

This week we will take a more structured look at forensic science, what it is, how it can contribute to investigations in general, and how it assisted the investigators in our specific case.

But first, this is a good time to return to the question of what forensic science is and we explore this in the next video.

Warning: Some of content presented in this course may be distressing to individuals, particularly younger learners. Notwithstanding, the material is representative of that encountered by forensic scientists and we have presented it in an objective and professional manner.

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This video is from the free online course:

Introduction to Forensic Science

University of Strathclyde